<?php

class Time
{
    /**
     * 返回今日开始和结束的时间戳
     *
     * @return array
     */
    public static function today()
    {
        return [
            mktime(0, 0, 0, date('m'), date('d'), date('Y')),
            mktime(23, 59, 59, date('m'), date('d'), date('Y'))
        ];
    }

    /**
     * 返回昨日开始和结束的时间戳
     *
     * @return array
     */
    public static function yesterday()
    {
        $yesterday = date('d') - 1;
        return [
            mktime(0, 0, 0, date('m'), $yesterday, date('Y')),
            mktime(23, 59, 59, date('m'), $yesterday, date('Y'))
        ];
    }

    /**
     * 返回本周开始和结束的时间戳
     *
     * @return array
     */
    public static function week()
    {
        $date=new DateTime();
        $date->modify('this week');
        $first_day_of_week=$date->format('Y-m-d');
        $date->modify('this week +6 days');
        $end_day_of_week=$date->format('Y-m-d');
        return [
            strtotime($first_day_of_week),
            strtotime($end_day_of_week)+ 24 * 3600 - 1
        ];
    }

    /**
     * 返回上周开始和结束的时间戳
     *
     * @return array
     */
    public static function lastWeek()
    {
        $timestamp = time();
        return [
            strtotime(date('Y-m-d', strtotime("last week Monday", $timestamp))),
            strtotime(date('Y-m-d', strtotime("last week Sunday", $timestamp))) + 24 * 3600 - 1
        ];
    }

    /**
     * 返回本月开始和结束的时间戳
     *
     * @return array
     */
    public static function month($everyDay = false)
    {
        return [
            mktime(0, 0, 0, date('m'), 1, date('Y')),
            mktime(23, 59, 59, date('m'), date('t'), date('Y'))
        ];
    }

    /**
     * 返回上个月开始和结束的时间戳
     *
     * @return array
     */
    public static function lastMonth()
    {
        $begin = mktime(0, 0, 0, date('m') - 1, 1, date('Y'));
        $end = mktime(23, 59, 59, date('m') - 1, date('t', $begin), date('Y'));

        return [$begin, $end];
    }

    /**
     * 返回今年开始和结束的时间戳
     *
     * @return array
     */
    public static function year()
    {
        return [
            mktime(0, 0, 0, 1, 1, date('Y')),
            mktime(23, 59, 59, 12, 31, date('Y'))
        ];
    }

    /**
     * 返回去年开始和结束的时间戳
     *
     * @return array
     */
    public static function lastYear()
    {
        $year = date('Y') - 1;
        return [
            mktime(0, 0, 0, 1, 1, $year),
            mktime(23, 59, 59, 12, 31, $year)
        ];
    }
    

    /**
     * 获取几天前零点到现在/昨日结束的时间戳
     *
     * @param int $day 天数
     * @param bool $now 返回现在或者昨天结束时间戳
     * @return array
     */
    public static function dayToNow($day = 1, $now = true)
    {
        $end = time();
        if (!$now) {
            list($foo, $end) = self::yesterday();
        }

        return [
            mktime(0, 0, 0, date('m'), date('d') - $day, date('Y')),
            $end
        ];
    }

    /**
     * 返回几天前的时间戳
     *
     * @param int $day
     * @return int
     */
    public static function daysAgo($day = 1)
    {
        $nowTime = time();
        return $nowTime - self::daysToSecond($day);
    }

    /**
     * 近一周时间月日数组
     * @return array
     */
    public static function weekDayArray(){
        return [
            date('m-d',self::daysAgo(7)),
            date('m-d',self::daysAgo(6)),
            date('m-d',self::daysAgo(5)),
            date('m-d',self::daysAgo(4)),
            date('m-d',self::daysAgo(3)),
            date('m-d',self::daysAgo(2)),
            date('m-d',self::daysAgo(1))
        ];
    }

    /**
     * 返回几天后的时间戳
     *
     * @param int $day
     * @return int
     */
    public static function daysAfter($day = 1)
    {
        $nowTime = time();
        return $nowTime + self::daysToSecond($day);
    }

    /**
     * 天数转换成秒数
     *
     * @param int $day
     * @return int
     */
    public static function daysToSecond($day = 1)
    {
        return $day * 86400;
    }

    /**
     * 秒数转 x天x时x分x秒
     * @param $time
     * @param bool $second
     * @return string
     */
    public static function  secondToStr($time,$second =false)
    {
        $arr = [86400 => '天', 3600 => '小时', 60 => '分'];
        if ($second){
            $arr[1] =  '秒';
        }
        $output = '';
        foreach ($arr as $key => $value) {
            if ($time >= $key) $output .= floor($time/$key) . $value;
            $time %= $key;
        }
        return $output;
    }

    /**
     * 周数转换成秒数
     *
     * @param int $week
     * @return int
     */
    public static function weekToSecond($week = 1)
    {
        return self::daysToSecond() * 7 * $week;
    }

    private static function startTimeToEndTime()
    {

    }
}